1. Field of the Invention
The present invention relates generally to a hand tool which allows a user to change the switch settings on a laser guided bombs and the like. More particularly, the present invention relates to a hand tool which allows a user to change the switch settings on a laser guided bomb when the PRF (pulse repetition frequency) code switch knobs on a laser guided are broken or lost during flight.
2. Description of the Prior Art
Laser Guided Bombs and Guided Bomb Units include guided control units, computer control groups or control sections which control the operation of the bombs. Each guided control unit or computer control group has a plurality of Pulse Repetition Frequency (PRF) Code switch knobs which are used to set the pulse repetition frequency for the Laser Guided Bomb.
There have been several occurrences in the past where the PRF code switch knobs have either been broken or lost. Without the switch knobs the laser guided bombs are rendered nonoperative since the switch knobs cannot be reattached externally. The PRF switch knobs are fabricated from plastic or other polymer and are secured to the knobs shaft by a retaining set screw. The threaded area of the knob which receives the set screw expands over time which loosens the set screw causing the knob to separate from its shaft and the bomb.
In addition, repeated use of the bomb for testing and harsh environments will often cause the switch knobs to separate from their shafts again rendering the laser guided bombs non-operative.
Currently, when the switch knobs are missing from a laser guided bomb, the bomb is sent to a rework facility for replacement of the missing switch knobs. Since the bombs have to be dis-assembled to replace the missing switch knobs and there are shipping cost associated with the transfer of a bomb to a rework facility, the cost to replace a bomb""s switch knobs can be several thousand dollars.
Accordingly, there is a need to provide an apparatus or tool which will allow a user to set the pulse repetition switch knobs on a laser guided bomb to a pulse repetition code for the laser guided bomb. In addition, the tool needs to have the capability of allowing a user to set the pulse repetition frequency for a laser guided bomb when one or more of the PRF switch knobs are broken or missing. It is also desirable that the tool be inexpensive, easy to fabricate, lightweight and portable.
The present invention overcomes some of the disadvantages of the past including those mentioned above in that it comprises a relatively simple in design yet highly effective and efficient switch key tool which allows a user to change the switch knob setting on a laser guided bomb and thereby change the pulse repetition frequency for the bomb.
The switch key tool has a cylindrical shaped body, a rectangular shaped member at one end and a xe2x80x9cDxe2x80x9d shaped opening at the opposite end of the tool. A user inserts the rectangular member into an elongated opening within the switch knob to change the switch knob setting. A first elongated white identification line on the black surface of the housing for switch key tool identifies for the user the current setting of the switch knob and provides a means for the user to set the switch knob to the new/required setting.
When the switch knob is missing, the user slides the xe2x80x9cDxe2x80x9d shaped opening of switch key tool over the shaft for the missing switch knob to change the PRF code setting for the missing knob. A second elongated white identification line on the black surface of the housing for switch key tool identifies for the user the current setting when the switch knob is missing and provides a means for the user to set the switch knob""s shaft to the new/required setting.
The switch key tool also has a U shaped handle which allows a user to attach the tool to a utility belt.